In the present society, a metamaterial is an artificial composite structure that exhibits superior physical properties not observed in the conventional material or nature. However, a unique electromagnetic feature of the metamaterial has a frequency band range, the unique electromagnetic feature is weakened or even disappeared if the metamaterial is out of the frequency band range.
Therefore, related technical persons begin to study a controllable metamaterial. In the recent research and development of these controllable metamaterial, there are mainly three types of controllable metamaterials: (1) a mechanical controllable metamaterial; (2) a controllable metamaterial loaded with a microwave switch; and (3) a controllable metamaterial loaded with a controllable material (for example, a ferrite, a liquid crystal material, and a graphene). For the mechanical controllable metamaterial, it is required that an amount of movement is precisely controlled; therefore, a volume of the metamaterial is relatively large, and an operation of the metamaterial is not easy. For the controllable metamaterial loaded with a microwave switch, a state of the metamaterial is related to a quantity of switches; and a sufficient quantity of switches need to be added to implement a sufficient quantity of states, thereby increasing complexity of a structure of the metamaterial. For the controllable metamaterial loaded with a controllable material, an adjustable frequency range of the metamaterial is not large; and a bias field needs to be externally applied to the metamaterial, thereby causing a complex structure of the metamaterial.
For the foregoing problems, no effective solution is currently proposed.